SailNet Community

SailNet Community (http://www.sailnet.com/forums/)
-   Seamanship & Navigation (http://www.sailnet.com/forums/seamanship-navigation/)
-   -   Rules Brainteaser (http://www.sailnet.com/forums/seamanship-navigation/57278-rules-brainteaser.html)

sailingSammy 08-21-2009 09:33 AM

Rules Brainteaser
 
The following situation takes place in open water on the Great Lakes outside of any marked channel.
A sailboat on the starboard tack is overtaking a power boat. Another sailboat on the port tack is to leeward of the others, and approaching from two points off the bow of the power boat. All vessels are on a course that will cause them to collide at the same location.
Under the inland rules which is the most priviledged vessel?

AdamLein 08-21-2009 09:52 AM

No vessels are "privileged" when they're all about to collide :P The rules identify actions each boat needs to take relative to each other boat so that everybody knows what to expect, not so that one boat gets to say, "If you rank us according to privilege, I come out on top, so if the rest of you will please stop colliding with me I would appreciate it."

That said I understand that the port tack boat gives way to the starboard tack boat, and the overtaking vessel gives way to the vessel overtaken.

fud 08-21-2009 12:41 PM

I agree with AdamLein, but to play along with the brainteaser:

The sailboat on the port tack
1) is give-way to the sailboat on the starboard tack
2) is stand-on to the power boat

The sailboat on the starboard tack
1) is give-way to the power boat (he's overtaking the powerboat)
2) is stand-on to the sailboat on a port tack

The power boat
1) is give-way to the sailboat on the port tack
2) is stand-on to the overtaking sailboat on the starboard tack

Like AdamLein said the rules are for each boat relative to one another and the problem comes in because the rules stated above don't specifically account for the scenario above. However, there are rules that do account for the "failure" of the specific rules, like:
RULE 17 - STAND-ON VESSEL
Quote:

b) When, from any cause, the vessel required to keep her course and speed finds herself so close that collision cannot be avoided by the action of the give-way vessel alone, she shall take such action as will best aid to avoid collision.
Basically everyone has the ultimate responsibilty to avoid collision regardless of the rules and whether the vessel is a stand-on, give-way or even both.

Diva27 08-21-2009 12:45 PM

Quote:

Originally Posted by sailingSammy (Post 515520)
The following situation takes place in open water on the Great Lakes outside of any marked channel.
A sailboat on the starboard tack is overtaking a power boat. Another sailboat on the port tack is to leeward of the others, and approaching from two points off the bow of the power boat. All vessels are on a course that will cause them to collide at the same location.
Under the inland rules which is the most priviledged vessel?

First off, let's remember that unlike the ISAF racing rules, colregs are not a "gotcha" rule system. Even ISAF rules are far less so today, obliging people to avoid collisions and be sportsmanlike.
But racing rules are helpful in how to approach these things as if you're on a protest jury. Start with the most fundamental, overriding rules and don't get lost or distracted in lesser details. In this case, I'd say begin by separating the apples from oranges: power from sail. In the situation you describe, power gives way to sail, period. So the powerboat must avoid both, and we can take it out of the equation. That leaves two sailboats.
With sailboats under the colregs, it helps a lot if you know the descending priority of basic rules under ISAF. Port-starboard (RULE 10) trumps all. Overtaking is rule 12. (Windward leeward is rule 11) It doesn't matter if starboard is overtaking port: starboard has right of way. (people forget this all the time on the race course).
Having said all that, let's remember colregs are designed to avoid collision and provide for seamanlike behaviour. Sailboats shouldn't maneuver in a way that places undue stress on the powerboat to avoid them. Racing rules also have the concept of "obstruction," in which a give-way vessel cannot do so because of it's obligations to avoid another vessel. That can come into play here, for many reasons. The powerboat might not be able to get out of the way of a sailboat promptly because one of them suddenly tacks in his path. A sailboat on port might not be able to avoid the one on starboard because of something the powerboat did. Large sailboats on starboard overtaking sailboats on port shouldn't feel entitled to plow right over them. (In racing, collision avoidance, even when you have right of way, is rule 14, and you can be disqualified even if you're in the right if you cause injury or damage.)
And just remember, if there's a collision under colregs, it's not going before a yacht club jury: it's going to end up in a civil suit and possibly with charges laid.
Over to everyone else.

Diva27 08-21-2009 12:56 PM

Just an elaboration on my comments where two converging sailboats are concerned with respect to port-starboard and clear ahead/clear astern. With sailboats, the concept of overtaking keeping clear applies to boats on the same tack, not opposite tacks. It's dangerous to confuse the situation by trying to ignore port-starboard. Two boats going to windward on opposite tacks can be converging and the guy on port can get it in his head that a slightly larger vessel approaching on starboard is going faster than him and is somehow "overtaking" him, and demand he keep clear. The rules should be followed just the same way when sailing downwind.

fud 08-21-2009 12:58 PM

Hi Diva27,

I have to confess that I know zero about ISAF racing rules, but I do want to comment on one thing you mentioned.
Quote:

In the situation you describe, power gives way to sail, period. So the powerboat must avoid both, and we can take it out of the equation.
That is not correct. When a sailboat is over taking a powerboat (even though this may not happen all that often) the power boat is the stand-on vessel and the sailboat is the give-way. I'm being picky, but also if the sailboat has the engine on (or perhaps in gear?) even if his sails are up (motor sailing) the sailboat is considered a powerboat and must follow those rules. Hope you don't mind my critique. The more I post here I'm sure you will get an opportunity to return the favor. :-)

Diva27 08-21-2009 01:13 PM

Quote:

Originally Posted by fud (Post 515588)
Hi Diva27,

I have to confess that I know zero about ISAF racing rules, but I do want to comment on one thing you mentioned.

That is not correct. When a sailboat is over taking a powerboat (even though this may not happen all that often) the power boat is the stand-on vessel and the sailboat is the give-way. I'm being picky, but also if the sailboat has the engine on (or perhaps in gear?) even if his sails are up (motor sailing) the sailboat is considered a powerboat and must follow those rules. Hope you don't mind my critique. The more I post here I'm sure you will get an opportunity to return the favor. :-)

I agree that if the sailboat is overtaking from astern, it should try to keep clear. But this is a little complicated. If you're in a powerboat and a sailboat under sail is holding a steady course and you choose to steer right in front of it, you're not giving way to the burdened vessel. In many situations like this, it's not a case of the sailboat is moving faster and following the powerboat dead astern, in which case the sailboat should go around the powerboat. Many times the two boats are converging, and it's up to the powerboat to recognize that convergence as the gap between them closes.
Your complication of the sailboat under power is right in that the sailboat at that point is no longer a sailboat (even if one or more sails are up). If you start turning on your motor while under sail, you're just another powerboat, which includes the fact that being on starboard is meaningless where other sailboats are concerned.
Good to chat about this.

Diva27 08-21-2009 02:08 PM

One more comment (I'm breaking in a Dell mini 10 right now , so bear with my verbosity). I cruise in a C&C 27 but I also have many years' experience cruising Georgian Bay in powerboats, the last being a Fairline 29, and I'm sympathetic to the plight of powerboaters where sailboats and colregs are concerned. As sailors, you can't count on powerboater to understand that your course is restricted when sailing hard on the wind, or that in light shifty winds you might have to change course 20-30 degrees all of a sudden not to go into irons. When I'm sailing I eyeball powerboats from a long way away and try to do as little as possible that will confuse them as the gap between us closes.
Having said that, some of the worst boaters I've seen for right-of-way infractions are sailors under power. Some people seem to have punched waypoints into a gps and refuse to alter course nomatter what. As a sailor, there's little that's more annoying than having to tack out of the way of a sailboat with the main up doing six knots under auxiliary.

Delirious 08-21-2009 11:59 PM

Quote:

Originally Posted by fud (Post 515588)
Hi Diva27,

I have to confess that I know zero about ISAF racing rules . . .

Nor do I. Nor would the powerboat captain involved. Nor most likely would either sailboat captain. That's why they would have zero bearing, except by coincedence, in a meeting situation as originally described unless it was during a race in which all parties had been informed that those rules would apply.

In U.S. waters I'd say the Rules of the Road as published by the U.S. Coast Guard would be the prime authority - in which case all vessels are obligated to avoid a collision, right or not, so I'd go with fud's earlier response.

http://www.navcen.uscg.gov/mwv/navrules/rotr_online.htm

Diva27 08-22-2009 08:28 AM

I agree that whatever keeps boats from running into each other is the best system. But I should have been clearer in the rules stuff. The basics of "when boats meet" (port-starboard, especially) in the rules have derived naturally from historic colregs, and should not contradict basic behaviour for sailboats whether a race is happening or not. I expect sailors to understand port-starboard and obey it, and not supplant it with some interpretation of their own of who is overtaking who. Courtesy and collision avoidance should ultimately prevail. And I still feel the powerboat as give-way boat should anticipate the situation and stay clear of both sailboats. It simplifies a tricky convergence.
good chat


All times are GMT -4. The time now is 09:33 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012